Portable ski sharpener

ABSTRACT

A power-operated device which utilizes the smooth ski bottom and one edge of the ski as guides for applying an abrasive element to the projecting metal edge at right angles to the bottom surface. No part of the sharpener extends more than a few millimeters past the metal edge to be sharpened so that mountings, screws, plates and cable anchors on the top and sides of the ski do not have to be removed.

United States Patent Inventor Stanley M. Richmond 331 Eugene MedicalCenter, Eugene, Oreg. 97401 App No. 837,556 Filed June 30, 1969 PatentedJune 22, 1971 PORTABLE SKI SHARPENER 9 Claims, 4 Drawing Figs.

U.S. CL 51/170 EB, 51/241 S, 144/134 D Int. Cl B241 23/00 FleldotSeareh51/170, 170.1, 1702,1703, 170.4, 241 S;144/70, 134.5, 137

[5 6] References Cited UNITED STATES PATENTS 2,282,145 5/1942 lndge51/170.2 3,119,207 1/1964 Nall... 51/170.l

3,159,951 12/1964 Winbauer 5l/170.1 3,412,508 11/1968 Schell, Jr. 51/170Primary Examiner-William R. Armstrong AnomeyLee R. Schermerhorn PORTABLESKI SHARPENER BACKGROUND OF THE INVENTION This invention relates to aportable power-operated tool for sharpening skis.

Modern skis are of composite construction from light metals, epoxyresins and fiberglas and most have laminated wooden cores. All of themhavelaterally projecting metal edges which have sharp right-anglecorners when the skis are new. These corners are formed on edge plateswhich have a flat sliding surface and a perpendicular side edge surface.This sharp right angle must be maintained for proficiency in skiing.

It is estimated that about two-thirds of all skiing is done on surfacesthat are not optimal. The desired powder snow is not ordinarilyavailable. Most skiing is done on packed surfaces and much skiing isdone on icy surfaces. Substantially all skiing is done on steep surfacesof varying degree of inclination.

In transversing any slanting surface, the sharp edges of the skis cutinto the surface and often the entire weight of the skier is balanced ononly 95 or 'A-inch width of the bottom sliding surface of the ski, thebalance of the running surface being out in the air. Furthermore, toinitiate certain turns and maneuvers, the skier sets his edges. This isa common term in the basics of ski instruction manuals which means toestablish a bite or a platform on the terrain from which to shove off orchange direction, this maneuver being executed while moving over theterrain at speeds ranging from 5 to 50 m.p.h. When the surface is icy orcontaminated with foreign materials, the square corners of the edgeplates are subject to considerable wear causing loss of control andrequiring frequent sharpenmg.

Heretofore, two different sharpening techniques have been available. Theskier may attempt the sharpening operation himself by putting a ski in avise and manually filing the vertical edge surfaces with a fiat file.The effectiveness of this technique is questionable. It requires a goodmechanic and a new sharp file because the edge plates are of a hardnessand toughness approaching that of the file. Filing is difficult becauseof obstructions in the regions that are most in need of sharpening. Thisis the midlength portion directly under the boot which does most of thework in establishing a bite in skiing maneuvers and is subject to themost wear. It is also in this area that the footplates and bindingsusually extend out over the edges of the ski from Ate l inch, ordinarilyon both sides of the ski. A filing operation in the hands of most skierstherefore leaves much to be desired.

Established ski shops sharpen skis either with a file or a stationaryband sander or bench grinder. The two latter types of machines require14 feet of linear space to run 7-foot skis through the stationaryequipment. Here, again, the footplates and bindings prevent operation ofa band sander or bench grinder in the midlength portion of the skiunless the fittings are first removed from the skis. Removal of thefittings, however, is objectionable because of the likelihood that someof the securing screws will not be screwed down firmly enough'inreplacement of the footplates and bindings to make watertightconnections. Moisture quickly deteriorates the wood laminations used inmost skis.

Thus, all methods of ski sharpening heretofore used have requiredremoval of the footplates and fittings at each sharpening in order to doan effective job. As a result of these various difficulties insharpening skis, at any given time the average pair of skis is in needof sharpening.

Objects of the invention are, therefore, to provide an improved portablepower-operated ski sharpener, to provide a ski sharpener which may beused successfully by the average skier without requiring the services ofa skilled mechanic, to provide a ski sharpener which does not requireremoval of footplates and bindings in order to sharpen the midlengthportion of the ski, and to provide a device of the type described whichis of relatively simple and inexpensive construction and which isconvenient to use.

SUMMARY OF THE INVENTION The present device is mounted on a flangedsoleplate which is adapted to slide on the fiat bottom surface of a skiturned upside down. It is not necessary to secure the ski in a vise. Itmay merely be laid across the two chairs. Skill is not required in theuse of the device.

All that is necessary is to hold the flange of the soleplate against theedge of the ski to be sharpened and slide thesoleplate along the lengthof the ski. The abrasive element is motor driven and spring tensioned tohold it against the vertical surface of the edge plate in the properposition to restore the sharp, square corner originally provided by themanufacturer. The parts are positioned and proportioned to clear anyprojecting parts of footplates and bindings so that these do not have tobe removed before sharpening the skis.

With convenient means available for sharpening his skis, the user willkeep them in better condition and experience greater pleasure in skiing.The device also provides a safety feature in that properly resharpcnedskis will always perform like new equipment, giving the skier asure-footedness and control that he does not experience with dull-edgedskis.

The invention will be better understood and additional objects andadvantages will become apparent from the following detailed descriptionof the preferred embodiment illustrated on the accompanying drawing.Various changes may be made in the details of construction andarrangement of parts and certain features may be used without others.All such modifications are included in the invention.

. BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective viewillustrating the operation of a ski sharpener embodying the principlesof the invention;

FIG. 2 is a view on the line 2-2 in FIG. 1;

FIG. 3 is a view on the line 3-3 in FIG. 2 with the footplate omitted;and

FIG. 4 is a view on the line 4-4 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 the ski 10 isturned upside down in order to present its bottom or running surface 11uppermost. The ski is equipped with a pair of hard metal edge plates 12,each having a flatbottom surface 13 in the plane of the general bottomsurface 11 of the ski and a flat vertical edge surface 14 which projectslaterally a small fraction of an inch beyond the vertical edge 15 of thebody of the ski. The comer 16 between the bottom surface 13 and edgesurface 14 is a angle as formed by the manufacturer.

As explained above, this square corner becomes worn and rounded in useand, if sharpened improperly, the angle may exceed 90. When either ofthese objectionable conditions occurs, the skis require resharpening torestore the original 90angle between surfaces 13 and 14. This isnecessary in order that the skier may set his edges and establish a bitein the snow or ice surface in changing direction as described above.When corner 16 becomes rounded or if the angle between surfaces 13 andI4 is substantially larger than 90, a dangerous condition existsresulting in loss of control of the skis in executing maneuvers. Thefunction of the present device is to grind off from the surface 14 theminimum amount of metal necessary to restore a square corner at 16 witha right-angle relationship between the surfaces 13 and 14.

FIG. 2 shows the conventional footplate 17 extending beyond both sideedges 15 of the ski. This footplate is omitted in the other views. Manyskis also have fastenings for bindings protruding from the side surface15 although these are not shown on the drawing.

The operation instrumentalities in the present device are mounted on aflat soleplate 20 having a narrow guide flange 21 extending in astraight line along the underside-of the plate as shown in FIG. 4. Thewidth or vertical dimension of flange 21 is only slightly greater thanthe thickness of edge plate 12 whereby the flange will clear thefootplate l7 and any fastenings for bindings on the side surfaces of thebody of the ski. Flange 21 is shaped as shown in FIG. 4 to clear theedge plate 12 and engage the side surface 15 closely adjacent edge plate12.

Mounted in upstanding position on soleplate is a handle 22 whereby theoperator may slide the plate 20 along the bottom surface of the skiwhile holding flange 21 against the side surface 15. The direction ofthis sliding movement is indicated by double-headed arrow A in FlG. 1.Handle 22 is equipped with a switch 23 and a circuit wire connection 24for energizing the motor 25.

Motor 25 is pivotally mounted on a vertical post 26 in an overhangingportion of soleplate 20 which projects outward beyond the flange 21. Thefront end of motor 25 is biased inward in the direction of arrow B by atension spring 28 which may be adjusted by a thumbscrew 29. The range ofthis swinging movement is limited by a stop 27 on the motor which willengage an abutment surface 27a on soleplate 20 when the device is not inuse. In use, the stop 27 normally remains spaced from abutment 27a asshown in F IG. 3.

Motor shaft 30 is equipped with a drive pulley 31 carrying an abrasivebelt 35. Belt 35 is trained around an idler pulley 36 on a pulley shaft37. Shaft 37 is mounted on one end of an arm 40 which is pivotallymounted on a horizontal pivot 41 on the front end of the motor housing.The belt is tightened by a vertical adjusting screw 42 having threadedengagement with the motor housing and bearing against the underside ofthe opposite end of arm 40. When a belt 35 is worn out, it may bereplaced by loosening the adjusting screw 42 allowing idler shaft 37 tomove upward.

The above-described parts are proportioned so that when abrasive belt 35is tightened in operating condition by adjusting screw 42, the axis ofidler shaft 37 will be on the level of edge plate 12 and no higher thanthe running surface of the edge plate. If desired, the idler shaft 37may be positioned slightly lower to form an angle of slightly less than90 between running surface 13 and edge surface 14. This is readilyaccomplished by mounting the motor 25 slightly closer to soleplate 20.In FIG. 2 the axis of shaft 37 is slightly below the plane of the bottomsurface of soleplate 20.

Shaft 37 is horizontal and the length of arm 40 and the position ofvertical pivot 26 are such that idler shaft 37 is parallel with the edgesurface 14 of edge plate 12 when the abrasive belt 35 on pulley 36engages the surface 14 in working position. This parallel relationshipmakes the whole width of the belt effective in working on edge surface14.

The belt is held in this working position by spring 2% and the pressureexerted by the belt against edge surface 14 is adjustable by thumbscrew29. As the soleplate 20 is moved along the ski by means of handle 22,the abrasive belt 35 operates on the whole length of one edge plate 12to sharpen the edge plate. Then by turning the device end for end, theopposite end plate 12 is sharpened in the same manner.

Idler pulley 36 is of very small diameter so as to clear any bindingattachments on the side surface 15 of the body of the ski. Thus, theidler pulley 36 will traverse the full length of the ski from end to endwith clearance above such attachments and the attachments and footplate17 do not have to be removed from the ski. A minimal amount of skill isrequired in the use of the device because it is only necessary to holdsoleplate 20 flat against the running surface of the ski and hold flange21 in engagement with side surface 15 throughout the length of theflange as the device is moved along the ski. When these two requirementsare fulfilled, the idler pulley 36 will be positioned on the level ofthe edge plate 12 and parallel therewith, making it practicallyimpossible to perform a faulty sharpening operation.

Although only the preferred embodiment has been illustrated anddescribed, the invention is capable of various possible modifications.For example, instead of training the abrasive belt 35 around twopulleys, a circular belt or band of shorter length may be mounted on adriven mandrel in position to work on edge surface 14 under the pressureapplied by spring 28. Also,-the motor 25 may be equipped wit a shortstroke saber saw-type of reciprocating mechanism to reciprocate a flatfile against edge surface 14 under the lateral pressure applied byspring 28. Still other modifications of the invention will occur topersons skilled in the art.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

A portable ski sharpener for a ski having metal edge plates on itsbottom surface, said sharpener comprising a soleplate adapted to slideon said bottom surface of the ski, guide means on said soleplatearranged to engage a side edge of the ski, a handle on said soleplatefor sliding the sharpener along said bottom surface of the ski, amotor-driven sharpening device comprising an abrasive band having aworking movement approximately perpendicular to said soleplate, meansmounted said device for transverse movement on said soleplate outwardlyfrom said guide means, and spring means tensioning said sharpeningdevice inwardly toward said edge plate to engage the edge thereof whenthe sharpener is in working position on said ski.

2. A ski sharpener as defined in claim 1, said guide means comprising aflange on said soleplate.

3. A ski sharpener as defined in claim 2, said flange being shaped toclear said edge plate and engage a portion of the side edge of the skiadjacent said edge plate.

4. A ski sharpener as defined in claim 1, said band comprising a beltmounted on a drive pulley and an idler pulley.

5. A ski sharpener as defined in claim 4, said idler pulley having anaxis parallel with said soleplate and adjacent the plane of theski-engaging surface of said soleplate.

6. A ski sharpener as defined in claim 5, said spring-tensioning meanscausing said idler pulley to press said abrasive belt against said edgeof said edge plate.

7. A ski sharpener as defined in claim 1, said mounting means comprisinga pivot on said soleplate.

8. A ski sharpener as defined in claim 7, said pivot being positioned onsaid soleplate outwardly from said guide means.

9. A portable ski sharpener for a ski having metal edge plates on itsbottom surface, said sharpener comprising a soleplate adapted to slideon said bottom surface of the ski, a guide flange on said soleplatearranged to engage a side edge of the ski, a handle on said soleplatefor sliding the sharpener along said bottom surface of the ski,perpendicular pivot on said soleplate, a motor mounted for pivotalmovement on said pivot, a drive pulley on said motor, an idler pulleymounted on said motor in a position adjacent one of said edge plateswhen the sharpener is in working position on said ski, an abrasive belton said pulleys, and spring means acting on said motor to press saidbelt against the edge of said edge plate.

1. A portable ski sharpener for a ski having metal edge plates on itsbottom surface, said sharpener comprising a soleplate adapted to slideon said bottom surface of the ski, guide means on said soleplatearranged to engage a side edge of the ski, a handle on said soleplatefor sliding the sharpener along said bottom surface of the ski, amotor-driven sharpening device comprising an abrasive band having aworking movement approximately perpendicular to said soleplate, meansmounted said device for transverse movement on said soleplate outwardlyfrom said guide means, and spring means tensioning said sharpeningdevice inwardly toward said edge plate to engage the edge thereof whenthe sharpener is in working position on said ski.
 2. A ski sharpener asdefined in claim 1, said guide means comprising a flange on saidsoleplate.
 3. A ski sharpener as defined in claim 2, said flange beingshaped to clear said edge plate and engage a portion of the side edge ofthe ski adjacent said edge plate.
 4. A ski sharpener as defined in claim1, said band comprising a belt mounted on a drive pulley and an idlerpulley.
 5. A ski sharpener as defined in claim 4, said idler pulleyhaving an axis parallel with said soleplate and adjacent the plane ofthe ski-engaging surface of said soleplate.
 6. A ski sharpener asdefined in claim 5, said spring-tensioning means causing said idlerpulley to press said abrasive belt against said edge of said edge plate.7. A ski sharpener as defined in claim 1, said mounting means comprisinga pivot on said soleplate.
 8. A ski sharpener as defined in claim 7,said pivot being positioned on said soleplate outwardly from said guidemeans.
 9. A portable ski sharpener for a ski having metal edge plates onits bottom surface, said sharpener comprising a soleplate adapted toslide on said bottom surface of the ski, a guide flange on saidsoleplate arranged to engage a side edge of the ski, a handle on saidsoleplate for sliding the sharpener along said bottom surface of theski, perpendicular pivot on said soleplate, a motor mounted for pivotalmovement on said pivot, a drive pulley on said motor, an idler pulleymounted on said motOr in a position adjacent one of said edge plateswhen the sharpener is in working position on said ski, an abrasive belton said pulleys, and spring means acting on said motor to press saidbelt against the edge of said edge plate.